True to the Music
Radial Engineering
J48 User Guide
14
How does Radial increase the rail voltage?
We take the input voltage and drive it through a special custom made DC-to-DC transformer. The transformer is coupled
to a timing chip that essentially drives the signal the same way as the newer switch mode or digital power amplifiers work.
This brings the current up to a workable level and creates a higher internal rail voltage to handle the dynamics.
What is phantom power?
Phantom power is a 48 volt DC supply that comes from the mixing console that was originally designed to provide power to
condenser microphones. The Radial J48 takes the phantom power and converts it using an internal switching power supply.
This allows the J48 to handle higher transients without the distortion associated with most active direct boxes.
Why does the LED not stay on?
We felt that every milliwatt of power should be diverted to provide maximum sound quality. Phantom power is limited and
LEDs require almost as much current as the whole J48 circuit. It will also save battery life if your Radial J48 is modified
to use batteries.
What happens if I am not getting any sound?
Check to make sure the phantom power is on at the console. Then check all your cables. Nine out of ten times, cables are
the culprits when it comes to no sound.
Is a flat frequency response better than a colored response?
This is a good question. When buying a large condenser microphone, you are not getting a flat mic, but getting a color or
flavor for your sound palette. Most studios boast a selection of mics and the sign of a good engineer is one that knows which
mic to use on what instrument in order to get a particular tone. With direct boxes, it is usually not the case. If the sound
of the guitar is not right, one will usually change the guitar, not the direct box. Therefore, we believe the role of the direct
box is to transport the original signal as faithfully as possible from the instrument to the destination and allow the engineer
and producer to make the artistic choices. Here’s more food for thought… should the direct box change the tone of the
instrument? If it makes your Strat sound fat, will it make your Les Paul muddy? We think a properly designed DI should be
faithful to the source. The Radial J48 direct box is natural and uncolored.
If my J48 ever fails, what do I do?
Simply contact your dealer or call Radial and we will issue a return authorization number and you can send it back to us for
repair. We do suggest that before you do so, visit the dealer where you bought it and have them check it before sending it
away. Often times, cables can be the problem.
